1. Field of the Invention
The present invention relates generally to shifting identity from one storage drive, such as a tape drive, to another storage drive without a host having any knowledge of the shift in identity.
2. Description of Related Art
Tape libraries, which generally house a multitude of tape cartridges, are often equipped with plurality of tape drives which, on occasion, may fail. When failure of a tape drive occurs, the tape library is shut down in order to swap the failed drive with a functional drive. The time over which the tape library is shut down is referred to “downtime”. FIG. 1 is used herein to assist in the description of how failed tape drives are replaced with functional tape drives.
FIG. 1 is an illustration of a tape library 100 that is linked with a first host 102 and a second host 104 via first switch system 106 and a second switch system 108. The tape library 100 is illustratively shown with twelve drive bays 110 wherein each drive bay 110 is configured to accommodate a tape drive 112. The tape library 100 possesses eight tape drives 112 and has four empty drive bays 110, each available to receive a tape drive 112. Each tape drive 112 is configured with a Serial Number and a World Wide Name. Hence, as illustratively shown, drive B 114 is linked to switch 1 and switch 2 and possesses a Serial Number (SN) and World Wide Name (WWN), which for purposes of illustration can be SN 1234 and WWN ABCD1234 respectively. If drive B 114 fails, drive B 114 is removed from the associated drive bay 110 and a new similar tape drive is installed with a new Serial Number and World Wide Name, such as SN 5678 and WWN EFGH5678, respectively. The tape library 100 needs to be rebooted in order for the host computers 102 and 104 to recognize that the tape library 100 possesses a new functional tape drive with SN 5678 for and WWN EFGH5678. The acts of replacing drive B 114 and rebooting the library 100 create a lengthy downtime whereby the tape library 100 is unavailable for storage operations.
Some tape library systems have improved the necessity to reboot the tape library by assigning the tape drive Serial Number and World Wide name to the drive bay instead of the tape drive. For purposes of illustration conforming similarly to the aforementioned example, the drive bay 116 can been assigned the SN 1234 and WWN ABCD1234. That way, if a new tape drive is installed as a replacement to a failed tape drive, the new tape drive will be recognized by host computers 102 and 104 as being the tape drive possessing the Serial Number 1234 and World Wide name ABCD1234, thus, eliminating the need to reboot of the tape library 100. Nonetheless, critical time is still lost when the failed tape drive is replaced by a functional tape drive.
In an effort to reduce downtime associated with replacing a failed tape drive with a functional tape drive within a tape library, both methods and apparatuses are disclosed herein. It is to innovations related to this subject matter that the claimed invention is generally directed.